Sensorimotor learning in Dab1scm (scrambler) mutant mice

Abstract Homozygous Dab1 scm mouse mutants with cell ectopias in cerebellar cortex and neocortex were compared with non-ataxic controls on two tests of motor coordination: rotorod and grid climbing. Even at the miminal speed of 4 rpm and unlike controls, none of the Dab1 scm mutants reached criterion on the constant speed rotorod. In contrast, Dab1 scm mutants improved their performances on the vertical grid over the course of the same number of trials. Thus, despite massive cerebellar degeneration, sensorimotor learning for equilibrium is still possible, indicating the potential usefulness of the grid-climbing test in determining residual functions in mice with massive cerebellar damage.